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Cui B, Meng S, Wang Z, Zhu X, Chen S, Liu W, Lin C, Yan W. Mechanism underlying the sustained stimulatory effects of energization on biomethane recovery from food waste post-energization cessation. ENVIRONMENTAL RESEARCH 2024; 261:119725. [PMID: 39096988 DOI: 10.1016/j.envres.2024.119725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Revised: 07/29/2024] [Accepted: 07/31/2024] [Indexed: 08/05/2024]
Abstract
Microbial electrolysis cell-assisted anaerobic digestion represents a promising approach for enhancing methanogenesis. This study investigated the impact of varying energy levels followed by long-term open circuit on biogas recovery from food waste. The results demonstrated that a mild voltage of 0.4 V resulted in 61.7% increase in methane yield, with a methane composition reaching 78.89% vol and a remarkable reduction in digestion time by 8 days. Additionally, the facilitated effects remained after prolonged periods of open-circuit. In-depth study revealed that energization significantly enhanced organic hydrolysis, redox proteins secretion and sludge electro-activity. Microbial communities showed that the ever-present energization enriched the hydrolytic bacterium and electrophiles. Subsequent investigations also revealed the upgradation of enzyme-encoding genes associated with hydrolysis and the synthesis of flavin and its homologs (i.e. ribE, ssuE and nfrA2). These findings collectively demonstrated the enduring benefits of energization were linked to the enhanced hydrolysis and regulated mediator-mediated electron transfer pathway.
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Affiliation(s)
- Baihui Cui
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China; School of Civil Engineering, Guangzhou University, Guangzhou, 510006, PR China
| | - Shengao Meng
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China
| | - Zi Wang
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China
| | - Xianzheng Zhu
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China
| | - Shuyan Chen
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China
| | - Wen Liu
- College of environment, Zhejiang University of Technology, Hangzhou, 310014, PR China
| | - Chunmian Lin
- College of environment, Zhejiang University of Technology, Hangzhou, 310014, PR China
| | - Wangwang Yan
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-Sen University, Gongchang Road, Guangming District, Guangdong, 518107, PR China.
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2
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Zheng T, Bian C, Xiao B, Chen X, Wang J, Li L. Performance enhancement of integrating microbial electrolysis cell on two-stage anaerobic digestion of food waste: Electro-methanogenic stage versus electro-two stages. BIORESOURCE TECHNOLOGY 2023; 386:129562. [PMID: 37506942 DOI: 10.1016/j.biortech.2023.129562] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023]
Abstract
The effects of microbial electrolysis cell (MEC) integration stage on two-stage anaerobic digestion (TSAD) of food waste (FW) were studied via semi-continuous experiments. The results showed that both MEC (with 1.2 V) integrations enhanced the performances of the TSADs, with the enhancement of electro-two stages being higher. The methane production of TSAD increased from 1.36 ± 0.04 L/L/d to 1.53 ± 0.05 L/L/d (electro-methanogenic stage) and 1.54 ± 0.04 L/L/d (electro-two stages) during the steady period. Electro-acidogenesis decreased propionic acid production and enhanced hydrogen production, while electro-methanogenesis promoted the conversion of volatile fatty acids to methane. The MEC integration improved energy recovery from the organic matter in FW by 11.65-16.15% and reduced the mass loss, with those of the electro-two stages being higher and the electro-methanogenic stage being dominant in the electro-two stages. The integration of MEC enhanced anaerobic fermentation by enriching Olsenella, norank_f__ST-12K33 and Proteiniphilum and improved methanogenesis by enriching Methanobacterium and Candidatus_Methanofastidiosum.
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Affiliation(s)
- Tianlong Zheng
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunlin Bian
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Civil Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Benyi Xiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xiangyu Chen
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juan Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Civil Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
| | - Lin Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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3
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Yu Q, Mao H, Zhao Z, Quan X, Zhang Y. Electromotive force induced by dynamic magnetic field electrically polarized sediment to aggravate methane emission. WATER RESEARCH 2023; 240:120097. [PMID: 37224670 DOI: 10.1016/j.watres.2023.120097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 04/26/2023] [Accepted: 05/16/2023] [Indexed: 05/26/2023]
Abstract
As a primary driving force of global methane production, methanogens like other living organisms are exposed to an environment filled with dynamic electromagnetic waves, which might induce electromotive force (EMF) to potentially influence the metabolism of methanogens. However, no reports have been found on the effects of the induced electromotive force on methane production. In this study, we found that exposure to a dynamic magnetic field enhanced bio-methanogenesis via the induced electromotive force. When exposed to a dynamic magnetic field with 0.20 to 0.40 mT of intensity, the methane emission of the sediments increased by 41.71%. The respiration of methanogens and bacteria was accelerated by the EMF, as the ratios of F420H2/F420 and NAD+/NADH of the sediment increased by 44.12% and 55.56%, respectively. The respiratory enzymes in respiration chains might be polarized with the EMF to accelerate the proton-coupled electron transfer to enhance microbial metabolism. Together with the enriched exoelectrogens and electrotrophic methanogens, as well as the increased sediment electro-activities, this study indicated that the EMF could enhance the electron exchange among extracellular respiratory microorganisms to increase the methane emission from sediments.
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Affiliation(s)
- Qilin Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Haohao Mao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhiqiang Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Xie Quan
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yaobin Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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4
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Sun A, Liu X, Zhang S, Yang Q, Huang S, Zhang N. Enhancing Nitrogen Removal Efficiency and Anammox Metabolism in Microbial Electrolysis Cell Coupled Anammox Through Different Voltage Application. BIORESOURCE TECHNOLOGY 2023:129283. [PMID: 37277003 DOI: 10.1016/j.biortech.2023.129283] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/07/2023]
Abstract
The slow growth and difficulty in cultivating anammox bacteria limit the rapid start-up of anammox process and effective microbial enrichment. In this study, microbial electrolysis cell (MEC) was coupled with anammox to investigate the effects of different applying voltage methods on substrate removal efficiency and rates, microbial community structure, anammox metabolism and metabolic pathways. The results showed that applying voltage not only improved NH4+-N removal efficiency and removal rates, but also promoted electron transfer efficiency, key enzyme activity and extracellular polymeric substances (EPS) secretion in the systems. Step-up voltage was more conducive to the growth of Candidatus_Kuenenia in the cathode, which promoted the rapid start-up of anammox and treating wastewater with low ammonia concentration. The main metabolic pathway in step-up voltage operation was hydrazine to nitrogen, while in constant voltage operation was hydroxylamine oxidation pathway. These findings provide a new insight into the enhancement and operation of anammox system.
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Affiliation(s)
- Anran Sun
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China
| | - Xiuhong Liu
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
| | - Shiyong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Qing Yang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Songqing Huang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China
| | - Nan Zhang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China
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5
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Yang B, Yu Q, Zhang Y. Applying Dynamic Magnetic Field To Promote Anaerobic Digestion via Enhancing the Electron Transfer of a Microbial Respiration Chain. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2138-2148. [PMID: 36696287 DOI: 10.1021/acs.est.2c08577] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Electrochemical methods have been reported to strengthen anaerobic digestion, but the continuous electrical power supply and the complicated electrode installed inside the digester have restricted it from practical use. In this study, a dynamic magnetic field (DMF) was placed outside a digester to induce an electromotive force to electrically promote anaerobic digestion. With the applied DMF, an electromotive force of 0.14 mV was generated in the anaerobic sludge, and a 65.02% methane increment was obtained from the anaerobic digestion of waste-activated sludge. Experiments on each stage of anaerobic digestion showed that acidification and methanogenesis that involve electron transfer of respiration chains were promoted with the DMF, while solubilization and hydrolysis less related to respiration chains were not enhanced. Further analysis indicated that the induced electromotive force polarized the protein-like substances in the sludge to increase the conductivity and capacitance of the sludge. Electrotrophic methanogens (Methanothrix) and exoelectrogens (Exiguobacterium) were enriched with DMF. The kinetic isotope effect test confirmed that electron transfer was accelerated with DMF. Consistently, the concentration ratio of co-enzymes (NADH/NAD+ and F420H2/F420) that reflects the electron exchange with respiration chains significantly increased. Applying the DMF seemed a more accessible strategy to electrically strengthen anaerobic digestion.
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Affiliation(s)
- Bowen Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Qilin Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yaobin Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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6
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Zhang S, Guan W, Sun H, Zhao P, Wang W, Gao M, Sun X, Wang Q. Intermittent energization improves microbial electrolysis cell-assisted thermophilic anaerobic co-digestion of food waste and spent mushroom substance. BIORESOURCE TECHNOLOGY 2023; 370:128577. [PMID: 36603750 DOI: 10.1016/j.biortech.2023.128577] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/30/2022] [Accepted: 01/01/2023] [Indexed: 06/17/2023]
Abstract
Microbial electrolysis cell-assisted thermophilic anaerobic digestion (MEC-TAD) is a promising method to improve anaerobic co-digestion efficiency; however, its application is restricted by high energy consumption. To improve the energy use efficiency of MEC-TAD, this study investigated the effect of different intermittent energization strategies on thermophilic co-digestion performance. Results revealed that an 18 h-ON/6h-OFF energization schedule resulted in the fastest electron transfer rate and the highest methane yield (364.3 mL/g VS). Mechanistic analysis revealed that 18 h-ON/6h-OFF resulted in the enrichment of electroactive microorganisms and increased abundance of enzyme-coding genes associated with energy metabolism (ntp, nuo, atp), electron transfer (pilA, nfrA2, ssuE), and the hydrogenotrophic methanogenic pathway. Finally, energy balance analysis revealed that 18 h-ON/6h-OFF had the highest net energy benefit (2.52 kJ) and energy conversion efficiency (110.76 %). Therefore, intermittent energization of MEC-TAD using an 18 h-ON/6h-OFF schedule can provide improved performance and more energy savings.
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Affiliation(s)
- Shuang Zhang
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Weijie Guan
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Haishu Sun
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Pan Zhao
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Wanqing Wang
- Tianjin College, University of Science and Technology Beijing, Tianjin 301811, China
| | - Ming Gao
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiaohong Sun
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Qunhui Wang
- Department of Environmental Science and Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Tianjin College, University of Science and Technology Beijing, Tianjin 301811, China.
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7
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Allam NE, Zakaria BS, Kuznetsov PV, Dhar BR, Ulrich AC. Mitigating methane emission from oil sands tailings using enzymatic and lime treatments. CHEMOSPHERE 2023; 313:137455. [PMID: 36470354 DOI: 10.1016/j.chemosphere.2022.137455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Engineering strategies to reduce greenhouse gases (GHGs) emissions by inhibiting methanogenesis in oil sands tailings have rarely been examined. In this study, we explored the potential impact of chemical treatment (lime) and biological treatment using enzymes (lysozyme and protease) on inhibiting methane emissions from tailings. Overall, treatment with protease 3%, lysozyme 3%, and lime 5000 ppm reduced CH4 production (by 52%, 28%, and 25%, respectively) and were weakly associated with the archaeal abundance. Enzymes treatment resulted in a higher reduction in CH4 production compared with lime treatment. A 3% lysozyme treatment suppressed CH4 production (the change in methane was 0.48 mmol) and reduced the degradation of hexane throughout the experiment. Similarly, 3% protease suppressed CH4 production throughout the experiment (the change in methane was 0.78 mmol), which could be attributed to the pH reduction to pH 4.9 at week 23 resulting from the formation of volatile fatty acids. Another possible mechanism could be the formation of toxic compounds, such as high nitrogen content, after protease treatment that inhibited the microbial community. The toxicity effect to Vibrio fischeri was greater with lysozyme 3% and protease 3% treatment than with lime treatment (124 TU and 76 TU, respectively). Lime treatment resulted in the highest reduction in 16S rRNA gene copies from 5.7 × 106 cells g-1 (control) to 2.7 × 105, 1.71 × 105, and 1.4 × 105 cells g-1 for 1600, 3500, and 5000 ppm treatments, respectively. This study supports further work to examine and determine the optimum conditions (e.g., enzyme and lime dosages) for CH4 inhibition.
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Affiliation(s)
- Nesma Eltoukhy Allam
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Basem S Zakaria
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Petr V Kuznetsov
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Bipro Ranjan Dhar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Ania C Ulrich
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
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8
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Yu Q, Mao H, Yang B, Zhu Y, Sun C, Zhao Z, Li Y, Zhang Y. Electro-polarization of protein-like substances accelerates trans-cell-wall electron transfer in microbial extracellular respiration. iScience 2023; 26:106065. [PMID: 36818305 PMCID: PMC9929677 DOI: 10.1016/j.isci.2023.106065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/22/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
Electrical stimulation has been used to strengthen microbial extracellular electron transfer (EET), however, the deep-seated reasons remain unclear. Here we reported that Bacillus subtilis, a typical gram-positive bacterium capable of extracellular respiration, obtained a higher EET capacity after the electrical domestication. After the electrical domestication, the current generated by the EET of B. subtilis was 23.4-fold that of the control group without pre-domestication. Multiple lines of evidence in bacterial cells of B. subtilis, their cell walls, and a model tripeptide indicated that the polarization of amide groups after the electrical stimulation forwarded the H-bonds recombination and radical generation of protein-like substances to develop extracellular electron transfer via the proton-coupled pattern. The improved electrochemical properties of protein-like substances benefited the trans-cell-wall electron transfer and strengthen extracellular respiration. This study was the first exploration to promote microbial extracellular respiration by improving the electrochemical properties of protein-like substances in cell envelopes.
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Affiliation(s)
- Qilin Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Haohao Mao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Bowen Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yahui Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Cheng Sun
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhiqiang Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yang Li
- School of Ocean Science and Technology, Dalian University of Technology, Panjin, Liaoning 124221, China
| | - Yaobin Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China,Corresponding author
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9
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Zhang Q, Wu M, Ailijiang N, Mamat A, Chang J, Pu M, He C. Impact of Voltage Application on Degradation of Biorefractory Pharmaceuticals in an Anaerobic-Aerobic Coupled Upflow Bioelectrochemical Reactor. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15364. [PMID: 36430083 PMCID: PMC9690855 DOI: 10.3390/ijerph192215364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/12/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Diclofenac, ibuprofen, and carbamazepine are frequently detected in the environment, where they pose a threat to organisms and ecosystems. We developed anaerobic-aerobic coupled upflow bioelectrochemical reactors (AO-UBERs) with different voltages, hydraulic retention times (HRTs), and types of electrode conversion, and evaluated the ability of the AO-UBERs to remove the three pharmaceuticals. This study showed that when a voltage of 0.6 V was applied, the removal rate of ibuprofen was slightly higher in the system with aerobic cathodic and anaerobic anodic chambers (60.2 ± 11.0%) with HRT of 48 h than in the control systems, and the removal efficiency reached stability faster. Diclofenac removal was 100% in the 1.2 V system with aerobic anodic and anaerobic cathodic chambers, which was greater than in the control system (65.5 ± 2.0%). The contribution of the aerobic cathodic-anodic chambers to the removal of ibuprofen and diclofenac was higher than that of the anaerobic cathodic-anodic chambers. Electrical stimulation barely facilitated the attenuation of carbamazepine. Furthermore, biodegradation-related species (Methyloversatilis, SM1A02, Sporomusa, and Terrimicrobium) were enriched in the AO-UBERs, enhancing pharmaceutical removal. The current study sheds fresh light on the interactions of bacterial populations with the removal of pharmaceuticals in a coupled system.
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Affiliation(s)
- Qiongfang Zhang
- Key Laboratory of Oasis Ecology of Education Ministry, College of Ecology and Environment, Xinjiang University, Urumqi 830017, China
- Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi 830017, China
| | - Mei Wu
- Key Laboratory of Oasis Ecology of Education Ministry, College of Ecology and Environment, Xinjiang University, Urumqi 830017, China
- Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi 830017, China
| | - Nuerla Ailijiang
- Key Laboratory of Oasis Ecology of Education Ministry, College of Ecology and Environment, Xinjiang University, Urumqi 830017, China
- Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi 830017, China
| | - Anwar Mamat
- School of Chemical Engineering and Technology, Xinjiang University, Urumqi 830017, China
| | - Jiali Chang
- Division of Environmental Engineering, School of Chemistry, Resources and Environment, Leshan Normal University, Leshan 614000, China
| | - Miao Pu
- Key Laboratory of Oasis Ecology of Education Ministry, College of Ecology and Environment, Xinjiang University, Urumqi 830017, China
- Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi 830017, China
| | - Chaoyue He
- Key Laboratory of Oasis Ecology of Education Ministry, College of Ecology and Environment, Xinjiang University, Urumqi 830017, China
- Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Urumqi 830017, China
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10
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de Albuquerque FP, Dastyar W, Mirsoleimani Azizi SM, Zakaria BS, Kumar A, Dhar BR. Carbon cloth amendment for boosting high-solids anaerobic digestion with percolate recirculation: Spatial patterns of microbial communities. CHEMOSPHERE 2022; 307:135606. [PMID: 35810875 DOI: 10.1016/j.chemosphere.2022.135606] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/30/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
The addition of conductive materials in anaerobic digestion (AD) is a promising method for boosting biomethane recovery from organic waste. However, conductive additives have rarely been investigated for the high-solids anaerobic digestion (HSAD). Here, the impact of adding carbon cloth in the solid phase of an HSAD system with percolate recirculation was investigated. Furthermore, spatial patterns of microbial communities in suspended biomass, percolate, and carbon cloth attached biofilm were assessed. Carbon cloth increased biomethane yield from source-separated organics (SSO) by 20% more than the unamended control by shortening the lag phase (by 15%) and marginally improving the methanogenesis rate constant (by ∼8%) under a batch operation for 50 days. Microbial community analysis demonstrated higher relative abundances of the archaeal population in the carbon cloth amended reactor than in unamended control (12%-21% vs. 5%-15%). Compared to percolate and suspension, carbon cloth attached microbial community showed higher enrichment of known electroactive Pseudomonas species along with Methanosarcina and Methanobacterium species, indicating the possibility of DIET-based syntrophy among these species.
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Affiliation(s)
| | - Wafa Dastyar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | | | - Basem S Zakaria
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Amit Kumar
- Mechanical Engineering, University of Alberta, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Bipro Ranjan Dhar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
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11
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Wang L, Yu Q, Sun C, Zhu Y, Wang Z, Zhang Y. Intermittent voltage induced sludge polarization to enhance anaerobic digestion. WATER RESEARCH 2022; 224:119071. [PMID: 36113237 DOI: 10.1016/j.watres.2022.119071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Intermittent voltage supply has been reported to improve the performance of electro-assisted anaerobic digestion but has not been well understood. In this study, an intermittent voltage of 0.6 V (1 day on-1 day off) was applied in an electro-assisted anaerobic digester to explore its effects. Compared to those without the voltage, the methane yield increased nearly by 20.0%, and organic decomposition increased by 9.5% with the intermittent voltage, which was similar to those with the continuous voltage. The amide groups of the sludge protein after the electro-treatment were polarized to enhance electron transfer and electron storage of protein-like substances of the sludge. Although the voltage was supplied intermittently, the increased conductivity and capacitance of the sludge and EPS could effectively transport electrons between exoelectrogens and electrotrophs (such as Firmicutes and Methanothrix) to promote the anaerobic digestion. This study explained the essence of electrochemical enhancement of anaerobic digestion from the perspective of molecular structure, that is, the polarization of functional groups by voltage could improve the sludge electro-activity to maintain effective interspecies electron transfer in the periodic voltage supply.
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Affiliation(s)
- Lujun Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Qilin Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Cheng Sun
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yahui Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhenxin Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yaobin Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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12
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Zhou H, Xing D, Ma J, Su Y, Zhang Y. Electrifying anaerobic granular sludge for enhanced waste anaerobic digestion and biogas production. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Zakaria BS, Guo H, Kim Y, Dhar BR. Molecular biology and modeling analysis reveal functional roles of propionate to acetate ratios on microbial syntrophy and competition in electro-assisted anaerobic digestion. WATER RESEARCH 2022; 216:118335. [PMID: 35358877 DOI: 10.1016/j.watres.2022.118335] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/08/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
This study examined the significance of propionate to acetate (HPr/HAc) ratios on microbial syntrophy and competition in microbial electrolysis cell-assisted anaerobic digestion (MEC-AD). In addition to molecular biology and phylogenetic analysis, a numerical MEC-AD model was developed by modifying Anaerobic Digestion Model No.1 to predict the effects of different HPr/HAc ratios (0.5, 1.5, 2.5, and 5). The HPr/HAc ratios of 0.5 and 1.5 maintained efficient syntrophy among electroactive bacteria, hydrogenotrophic methanogens, and homoacetogens, leading to higher methane yields. In contrast, higher HPr/HAc ratios of 2.5 and 5 were detrimental to methanogenesis. Both microbial community analysis and numerical modeling results suggested that higher propionate levels could promote the enrichment of H2-utilizing acetogens, thereby triggering their competition with hydrogenotrophic methanogens. Moreover, protein fraction in extracellular polymeric substances and the relative expression of genes associated with extracellular electron transfer in both anode and cathode biofilms were markedly decreased with increasing HPr/HAc ratios, indicating partial inhibition of microbial electroactivity. Overall, these results illuminate deep insight into anaerobic syntrophy, contributing to the process kinetics and methane yields in MEC-AD systems. Furthermore, from a practical viewpoint, the results can also be helpful in effective control of MEC-AD operation without propionate accumulation.
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Affiliation(s)
- Basem S Zakaria
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Hui Guo
- Civil Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Younggy Kim
- Civil Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Bipro Ranjan Dhar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
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14
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Zhi Z, Pan Y, Lu X, Wang J, Zhen G. Bioelectrochemical regulation accelerates biomethane production from waste activated sludge: Focusing on operational performance and microbial community. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152736. [PMID: 34974012 DOI: 10.1016/j.scitotenv.2021.152736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/30/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Bioelectrochemical regulation represents a newly emerging strategy to enhance anaerobic digestion (AD) of biowastes. Herein, a novel microbial electrolysis cell (MEC) system, equipped with a pair of carbon brush anode and hybrid Ti/RuO2-graphite felt cathode, was developed to explore the role of bioelectrochemical regulation in the proliferation/enrichment of functional microbes and methanation of waste activated sludge. The methane production was significantly improved by applying bioelectrochemical regulation. The maximum methane yield was 16.4 mL/L-reactor at the applied external voltage 1.2 V and solids retention time 15 d, 8.6-time higher than that of a single AD. Further analysis demonstrated that bioelectrochemical regulation selectively enriched electroactive fermentative partners and methanogens (especially Thermincola, Methanobacterium) in the MEC-AD system and built up a robust syntrophic interaction. This drove the decomposition of complex organics and concurrent bioelectroreduction of CO2 in biogas and subsequently enhanced methane generation. Besides, bioelectrochemical simulation attenuated N2O emissions and enhanced the dewaterability of digested sludge.
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Affiliation(s)
- Zhongxiang Zhi
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, Shanghai 200092, PR China
| | - Yang Pan
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Nanjing Innovation Center for Environmental Protection Industry Co. Ltd., Nanjing 211106, PR China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Institute of Eco-Chongming (IEC), 3663 N. Zhongshan Rd., Shanghai 200062, PR China
| | - Jianhui Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai 200062, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China.
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15
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Brandão Lavender M, Pang S, Liu D, Jourdin L, Ter Heijne A. Reduced overpotential of methane-producing biocathodes: Effect of current and electrode storage capacity. BIORESOURCE TECHNOLOGY 2022; 347:126650. [PMID: 34974095 DOI: 10.1016/j.biortech.2021.126650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/23/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
Cathode overpotential is a key factor in the energy efficiency of bioelectrochemical systems. In this study the aim is to demonstrate the role of applied current density and electrode storage capacity on cathode overpotential. To do so, eight reactors using capacitive granular activated carbon as cathode material were operated. Four reactors were controlled at -5 A m-2 and four at -10 A m-2. Additionally, to evaluate the electrode storage capacity, weekly charge/discharge tests were conducted for half of the reactors at each applied current density. Results show that cathode potential as high as -0.50 V vs. Ag/AgCl can be reached. Furthermore, the resulting low cathode overpotential is both dependent on applied current density and employment (or not) of charge/discharge tests: reactors at -10 A m-2 without charge/discharge regimes did not result in increasing cathode potential whereas reactors at -5 A m-2 and at -10 A m-2 with charge/discharge regimes did.
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Affiliation(s)
- Micaela Brandão Lavender
- Environmental Technology, Wageningen University, P.O. Box 17, Wageningen, The Netherlands; Paqell B.V., Reactorweg 301, 3542 AD Utrecht, The Netherlands
| | - Siqi Pang
- Environmental Technology, Wageningen University, P.O. Box 17, Wageningen, The Netherlands
| | - Dandan Liu
- Environmental Technology, Wageningen University, P.O. Box 17, Wageningen, The Netherlands; Paqell B.V., Reactorweg 301, 3542 AD Utrecht, The Netherlands
| | - Ludovic Jourdin
- Environmental Technology, Wageningen University, P.O. Box 17, Wageningen, The Netherlands
| | - Annemiek Ter Heijne
- Environmental Technology, Wageningen University, P.O. Box 17, Wageningen, The Netherlands.
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16
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Wang XT, Zhang YF, Wang B, Wang S, Xing X, Xu XJ, Liu WZ, Ren NQ, Lee DJ, Chen C. Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process - A review. BIORESOURCE TECHNOLOGY 2022; 346:126641. [PMID: 34973405 DOI: 10.1016/j.biortech.2021.126641] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) was proved to increase methane productivity and methane yield of waste activated sludge (WAS) by establishing direct interspecies electron transfer method and enriching functional microorganisms. This review first summarized the pretreatment methods of WAS for MEC-AD and then reviewed the reactor configurations, operation parameters, and the economic benefit of MEC-AD. Furthermore, the enhancement mechanisms of MEC-AD were reviewed based on the analysis of thermodynamics and microbial community. It was found that the decrease of hydrogen partial pressure due to the hydrogenotrophic methanogens enriched in cathodic biofilm and direct interspecies electron transfer between exoelectrogens and anode were the core mechanisms for improving acidogenesis, acetogenesis, and methanogenesis. Finally, the potentially technological issues that need to be addressed to increase energy efficiency in large-scale MEC-AD processes were discussed.
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Affiliation(s)
- Xue-Ting Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China; Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Yi-Feng Zhang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Bo Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Song Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Xue Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Xi-Jun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Wen-Zong Liu
- School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.
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17
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Wang W, Lee DJ, Lei Z. Integrating anaerobic digestion with microbial electrolysis cell for performance enhancement: A review. BIORESOURCE TECHNOLOGY 2022; 344:126321. [PMID: 34785334 DOI: 10.1016/j.biortech.2021.126321] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic digestion has been recognized as promising technology for bioenergy production, while the bottlenecks including long start up times, low methane contents, and susceptibility toward environmental change attenuate the process benefits. Integrating microbials electrolysis cell (MEC) with anaerobic digestion (AD) has been recognized as a promising strategy for alleviate the performance bottleneck. This review summarized and updated the current researches that utilize MEC-AD for enhanced methane production from biomass. The integrated AD-MEC was first elucidated, followed by illustrations on strategies for process performance enhancements, parameters effects, and the associated applications. Finally, the challenges and prospects were outlined in this work.
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Affiliation(s)
- Wei Wang
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan; Chemistry Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan; Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong
| | - Zhongfang Lei
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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18
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Hyun Chung T, Ranjan Dhar B. A multi-perspective review on microbial electrochemical technologies for food waste valorization. BIORESOURCE TECHNOLOGY 2021; 342:125950. [PMID: 34852436 DOI: 10.1016/j.biortech.2021.125950] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/08/2021] [Accepted: 09/12/2021] [Indexed: 06/13/2023]
Abstract
The worldwide generation of food waste (FW) has been increasing enormously due to the growing food industry and population. However, FW contains a large amount of biodegradable organics that can be converted to clean energy, which can potentially minimize the utilization of fossil fuels. Conventional biowaste valorization technologies, such as anaerobic digestion and composting, have been adopted for FW management for recovering useful biogas and compost. However, they are often limited by high capital and operation costs, low recovery efficiency, slow process kinetics, and system instability. On the other hand, microbial electrochemical technologies (METs) have been highly promising for efficiently harvesting bioenergy and high value-added products from FW. Hence, this article critically reviews up-to-date studies on applying various METs regarding their value-added products recovery efficiencies from FW. Moreover, this review lists existing challenges, ways to optimize the system performance and provides perspectives on future research needs.
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Affiliation(s)
- Tae Hyun Chung
- Department of Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9, Canada
| | - Bipro Ranjan Dhar
- Department of Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9, Canada.
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19
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Mao Z, Cheng S, Sun Y, Lin Z, Li L, Yu Z. Enhancing stability and resilience of electromethanogenesis system by acclimating biocathode with intermittent step-up voltage. BIORESOURCE TECHNOLOGY 2021; 337:125376. [PMID: 34116281 DOI: 10.1016/j.biortech.2021.125376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 06/12/2023]
Abstract
Electromethanogenesis (EMG) system could efficiently convert CO2 to CH4 by using excess renewable electricity. However, the fluctuation and interruption of renewable electricity will adversely affect the biocathode and therefore the CH4 production of the EMG system. In this work, a novel biocathode acclimation strategy with intermittent step-up voltage (ISUV) was proposed to improve the stability and resilience of the EMG system against the unstable input of renewable power. Compared with the intermittent application of constant voltage (IACV), the ISUV increased the rate of CH4 production by 11.7 times with the improvement of the stability and resilience by 56% and 500%, respectively. Morphology and microflora structure analysis revealed that the biofilm enriched with ISUV exhibited a compact microflora structure with high-density cells and nanowires interconnected. This study provided a novel effective strategy to regulate the biofilm structure and enhance the performance of the EMG system.
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Affiliation(s)
- Zhengzhong Mao
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Shaoan Cheng
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, PR China.
| | - Yi Sun
- Powerchina Huadong Engineering Corporation Limited, Hangzhou 311122, PR China
| | - Zhufan Lin
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Longxin Li
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, PR China
| | - Zhen Yu
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, PR China
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20
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Huang Q, Liu Y, Dhar BR. Pushing the organic loading rate in electrochemically assisted anaerobic digestion of blackwater at ambient temperature: Insights into microbial community dynamics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 781:146694. [PMID: 33812109 DOI: 10.1016/j.scitotenv.2021.146694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Decentralized blackwater treatment by anaerobic digestion is being considered as a sustainable sanitation concept. However, the low biodegradability and complex composition restrictedly limited the treatability of blackwater, resulting in requirements of low operational organic loading rates (OLRs). In this study, a microbial electrolysis cell assisted anaerobic digester (MEC-AD) treating vacuum toilet blackwater was successfully operated for 420 days at OLRs ranging from 0.77 to 3.03 g COD/L-d in 6 stages (including an open-circuit Stage 5) at ambient temperature. Based on the steady-state results from different stages, the highest methane yield (42.4% out of 45% biochemical methane potential value) was achieved in Stage 1 with an OLR of 0.77 g COD/L-d. At the same OLR of ~3.0 g COD/L-d, Stage 4 (32.4%) and Stage 6 (35.2%) showed significantly higher methane yield (p < 0.01) than open-circuit Stage 5 (24.1%). The lowest COD removal efficiency of 31.8% was observed in Stage 5 with short-chain volatile fatty acids (SCVFAs) accumulated to ~1000 mg/L, which was more than double the values of Stage 4 and 6. The microbial community analysis revealed that the applied potential did not significantly affect archaeal diversity but largely increased the archaeal abundance on the cathode, and led the bacterial community shift with the enrichment of specific electroactive bacteria. Microbial co-occurrence network analysis further confirmed the positive correlations between known electroactive bacteria and electrotrophic methanogens. Moreover, electric energy consumed by the MEC-AD system was fully recovered as biomethane.
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Affiliation(s)
- Qi Huang
- Department of Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9, Canada.
| | - Bipro Ranjan Dhar
- Department of Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9, Canada
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21
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Shekhar Bose R, Zakaria BS, Kumar Tiwari M, Ranjan Dhar B. High-rate blackwater anaerobic digestion under septic tank conditions with the amendment of biosolids-derived biochar synthesized at different temperatures. BIORESOURCE TECHNOLOGY 2021; 331:125052. [PMID: 33812134 DOI: 10.1016/j.biortech.2021.125052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Septic tanks have been widely used for blackwater treatment in developing countries, while high-rate septic tanks with improved methane recovery are yet to be achieved. This study investigated biosolids-derived biochar (synthesized at 300℃, 425℃, and 550℃) as an additive for developing high-rate septic tanks. The experiments were conducted with anaerobic bioreactors operated with synthetic blackwater under septic tank conditions. All biochar amended reactors demonstrated a steady increase in daily methane production for increasing OLR from 0.08 to 3 g COD/L/d. The control reactor showed significant process disturbances at OLRs ≥ 2 g COD/L/d with an accumulation of volatile fatty acids followed by pH drop. At OLR of 3 g COD/L/d, the daily methane production from biochar amended reactors was ~ 4.3 times higher than the control (300 vs. 70 mL per day). Biochar addition established a robust microbiome consisted of a higher abundance of hydrogenotrophic and acetoclastic methanogens and hydrogen-producing fermentative bacteria.
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Affiliation(s)
- Raj Shekhar Bose
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada; School of Water Resources, Indian Institute of Technology Kharagpur, WB, India
| | - Basem S Zakaria
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada
| | - Manoj Kumar Tiwari
- School of Water Resources, Indian Institute of Technology Kharagpur, WB, India
| | - Bipro Ranjan Dhar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada.
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22
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Singh A, Kumar V. Recent developments in monitoring technology for anaerobic digesters: A focus on bio-electrochemical systems. BIORESOURCE TECHNOLOGY 2021; 329:124937. [PMID: 33712339 DOI: 10.1016/j.biortech.2021.124937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
With the increasing popularity of waste to energy conversion, demand for large-scale operation of anaerobic digestors has emerged in the market. However, the process instabilities in anaerobic digestors limit the expansion of facilities to high loading rates. The irregularities in the process can be addressed directly by altering the feedstock characteristics provided an on-hand, robust, and sensitive monitoring device is available. In this context, the bioelectrochemical system has emerged as an excellent tool for monitoring and optimizing the anaerobic process within the reactor. This article reviews the gradual evolution in techniques and approaches for monitoring of anaerobic digestion (AD) process. An analysis of the recently popular biosensing techniques has been done with a focus on the bioelectrochemical monitoring system and its operation mode. A brief attempt to highlight the current challenges in the field of bioelectrochemical process monitoring for AD has also been made, which can be supportive of future research.
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Affiliation(s)
- Ankur Singh
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand 826004, India
| | - Vipin Kumar
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand 826004, India.
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23
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Zakaria BS, Dhar BR. Characterization and significance of extracellular polymeric substances, reactive oxygen species, and extracellular electron transfer in methanogenic biocathode. Sci Rep 2021; 11:7933. [PMID: 33846480 PMCID: PMC8041852 DOI: 10.1038/s41598-021-87118-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 03/24/2021] [Indexed: 02/01/2023] Open
Abstract
The microbial electrolysis cell assisted anaerobic digestion holds great promises over conventional anaerobic digestion. This article reports an experimental investigation of extracellular polymeric substances (EPS), reactive oxygen species (ROS), and the expression of genes associated with extracellular electron transfer (EET) in methanogenic biocathodes. The MEC-AD systems were examined using two cathode materials: carbon fibers and stainless-steel mesh. A higher abundance of hydrogenotrophic Methanobacterium sp. and homoacetogenic Acetobacterium sp. appeared to play a major role in superior methanogenesis from stainless steel biocathode than carbon fibers. Moreover, the higher secretion of EPS accompanied by the lower ROS level in stainless steel biocathode indicated that higher EPS perhaps protected cells from harsh metabolic conditions (possibly unfavorable local pH) induced by faster catalysis of hydrogen evolution reaction. In contrast, EET-associated gene expression patterns were comparable in both biocathodes. Thus, these results indicated hydrogenotrophic methanogenesis is the key mechanism, while cathodic EET has a trivial role in distinguishing performances between two cathode electrodes. These results provide new insights into the efficient methanogenic biocathode development.
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Affiliation(s)
- Basem S. Zakaria
- grid.17089.37Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9 Canada
| | - Bipro Ranjan Dhar
- grid.17089.37Civil and Environmental Engineering, University of Alberta, 9211-116 Street NW, Edmonton, AB T6G 1H9 Canada
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24
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Bio-Electrochemical Enhancement of Hydrogen and Methane Production in a Combined Anaerobic Digester (AD) and Microbial Electrolysis Cell (MEC) from Dairy Manure. SUSTAINABILITY 2020. [DOI: 10.3390/su12208491] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anaerobic digestion (AD) is a biological-based technology that generates methane-enriched biogas. A microbial electrolysis cell (MEC) uses electricity to initiate bacterial oxidization of organic matter to produce hydrogen. This study determined the effect of energy production and waste treatment when using dairy manure in a combined AD and MEC (AD-MEC) system compared to AD without MEC (AD-only). In the AD-MEC system, a single chamber MEC (150 mL) was placed inside a 10 L digester on day 20 of the digestion process and run for 272 h (11 days) to determine residual treatment and energy capacity with an MEC included. Cumulative H2 and CH4 production in the AD-MEC (2.43 L H2 and 23.6 L CH4) was higher than AD-only (0.00 L H2 and 10.9 L CH4). Hydrogen concentration during the first 24 h of MEC introduction constituted 20% of the produced biogas, after which time the H2 decreased as the CH4 concentration increased from 50% to 63%. The efficiency of electrical energy recovery (ηE) in the MEC was 73% (ηE min.) to 324% (ηE max.), with an average increase of 170% in total energy compared to AD-only. Chemical oxygen demand (COD) removal was higher in the AD-MEC (7.09 kJ/g COD removed) system compared to AD-only (6.19 kJ/g COD removed). This study showed that adding an MEC during the digestion process could increase overall energy production and organic removal from dairy manure.
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